A 5.60 g sample of a weak acid with
Ка 1.3 x 10-4 was combined with 5.00 mL of
5.80 mol L-1 NaOH and the resulting solution
was diluted to 750 mL. The measured pH of the
solution was 4.35.
What is the molar mass of the weak acid
Answer:
pKa = - log Ka = - log (1.3 * 10^-4) = 3.886 5.20 mL of 6.20 M NaOH = 0.00520 L * 6.20 mole…
Explanation:
explain why an atom can only emit specific wavelengths of light and not every possible wavelength
Answer:
The electrons in an atom can only occupy certain allowed energy levels to a lower one, the excess energy is emitted as a photon of light, with its wavelength dependent on the change in electron energy. This is why an atom can only emit specific wavelengths of light and not every possible wavelength.
Substance whose smell changes in acidic or basic solutions
Answer:
Olfactory indicators
Explanation:
The substance whose odour changes in an acidic of basic medium are called olfactory indicators. In an olfactory indicator , smell varies depending on whether it is mixed with an acidic or basic solution.
Compost from vegetable peelings can be used as plant fertilizer. * a. reduce b. resuse c. recycle d. recover
Answer:
Is letter B
Explanation:
Hope it helps :))
How many atoms of Xe does 7.84 moles of Xe contain?
When 3.93 grams of lactic acid, CHoOs(s), are burned in a bomb
calorimeter that has a total heat capacity of 10.80 kJ-K-1, the
temperature of the calorimeter increases by 5.43 K. Assume AHrxn
=
AErxn. Given that AH°f of H¿O(I) = -285.8 kJ-mol-1 and AH°f of CO:(g)
= -393.5 kJ• mol-1, calculate the AH°f of lactic acid.
The heat released in the combustion of lactic acid is absorbed by the
calorimeter and in the decomposition of the lactic acid.
ΔH°f of lactic acid is approximately -716.2 kJ
Reasons:
Known parameters are;
Mass of the lactic acid = 3.93 grams
Heat capacity of the bomb calorimeter = 10.80 kJ·K⁻¹
Change in temperature of the calorimeter, ΔT = 5.34 K
ΔHrxn = ΔErxn
ΔH°f of H₂O(l) = -285.8 kJ·mol⁻¹
ΔH°f of CO₂(g) = -393.5 kJ·mol⁻¹
The chemical equation for the reaction is presented as follows;
C₃H₆O₃ + 2O₂ → 3CO₂ + 3H₂OThe heat of the reaction = 10.80 kJ·K⁻¹ × 5.34 K = 57.672 kJ
Molar mass of C₃H₆O₃ = 90.07 g/mol
Number of moles of C₃H₆O₃ = [tex]\dfrac{3.93 \, g}{90.07 \, g/mol}[/tex] = 0.043633 moles
Number of moles of CO₂ produced = 3 × 0.043633 moles = 0.130899 moles
Heat produced = 0.130899 mole × -285.8 kJ·mol⁻¹ = -37.4109342 kJ
Moles of H₂O produced = 0.130899 moles
Heat produced = 0.130899 mole × -393.5 ≈ -51.51 kJ
Therefore, we have;
Heat absorbed by the lactic acid = ΔH°f of H₂O + ΔH°f of CO₂ + Heat absorbed by the calorimeter
Which gives;
Heat absorbed by lactic acid = -37.4109342 kJ - 51.51 kJ + 57.672 kJ ≈ -31.249 kJ
The heat absorbed by the lactic acid ≈ -31.249 kJ
[tex]\Delta H^{\circ}f \ of \ C_3H_6O_3 = \dfrac{-31.249}{0.043633} \approx -716.2[/tex]
ΔH°f of C₃H₆O₃ ≈ -716.2 kJ
Heat of formation of lactic acid ≈ -716.2 kJ.
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how many gallons in one cubic foot?
Answer:
1cf gallon=7.481 us liquid gallon
4. Some biologists declare "structure determines functions." The 3-D molecular geometry in small molecules (or units of molecules) are critical in the final shape of larger structures. Give an example, not found in your notes or textbook that illustrate how a change a final shape can affect how the structure functions (or how other substances interact with it) and explain your choice.
explain the role of sulphuric acid in limit test for iron
does ch3 have resonance structure?
Answer:
yes
Explanation:
if u watch or look closely u will observe it
The CH₃ has resonance structures as it has odd number of hydrogen atoms.
In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures ,also variously known as resonance structures or canonical structures into a resonance hybrid (or hybrid structure) in valence bond theory. It has particular value for analyzing delocalized electrons where the bonding cannot be expressed by one single Lewis structure.
Thus, CH₃ has resonance structures as it has odd number of hydrogen atoms.
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what mass of water (in grams) is produced by the reaction of 23.0 g of SiO2?
The mass of water produced by the reaction of the 23 g of [tex]SiO_2[/tex] is 13.8 g.
The given chemical reaction;
[tex]4Hf (g) \ + \ SiO_2 (s) \ --> \ SiF_4(g) \ + \ 2H_2O(l)[/tex]
In the given compound above, we can deduce the following;
molecular mass of [tex]SiO_2[/tex] = 28 + (2 x 16) = 60 gmolecular mass of [tex]2H_2O[/tex] = 2(18) = 36 g60 g of [tex]SiO_2[/tex] --------- 36 g of water
23 g of [tex]SiO_2[/tex] ------------- ? of water
[tex]mass \ of \ water = \frac{23 \times 36}{60} = 13.8 \ g \ of \ water[/tex]
Thus, the mass of water produced by the reaction of the 23 g of [tex]SiO_2[/tex] is 13.8 g.
"Your question is not complete, it seems to be missing the following information";In the reaction of the given compound, [tex]4Hf (g) \ + \ SiO_2 (s) \ --> \ SiF_4(g) \ + \ 2H_2O(l)[/tex], what mass of water (in grams) is produced by the reaction of 23.0 g of SiO2?
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Is water wet? Why or why not
Answer: umm, yes? DUH
Explanation: touch some falling out of a tap
Answer:
Water is wet,
Explanation:
in the sense of being a liquid which flows easily, because its viscosity is low, which is because its molecules are rather loosely joined together. So it is wet.
The temperature at which a solid melts is the same as the temperature at which its liquid form solidifies (true or false)
its false not true................
Answer:
True
Explanation:
This is true because, upon cooling the particles in a liquid loses energy, stops moving and remains constant and the forms a solid.
Therefore we can say the freezing point and melting point occurs at the same temperature
helppppppppppppppppppppppppppp
Answer:
C is the correct option.
Explanation:
When water reaches 100°C it starts evaporating and the molecules of water turns to vapor.
Select the statements that correctly describe an asteroid. Check all that apply
Largest of the space rocks found orbiting the Sun.
Smallest of the space rocks found orbiting the Sun.
most are found between Mars and Jupiter
most are found between Jupiter and Saturn
Answer:
Explanation:
Most of this ancient space rubble can be found orbiting the Sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta – the largest at about 329 miles (530 kilometers) in diameter – to bodies that are less than 33 feet (10 meters) across.
What will happen to the pH of sodium bicarbonate if vinegar is added to it?
Answer:
The overall chemical reaction between baking soda (sodium bicarbonate) and vinegar (weak acetic acid) is one mole of solid sodium bicarbonate reacts with one mole of liquid acetic acid to produce one mole each of carbon dioxide gas, liquid water, sodium ions, and acetate ions. The reaction proceeds in two steps
28.5 g of iron shot is added to a graduated cylinder containing 45.50 mL of water. The water level rises to the 49.10 mL mark. From this information, calculate the density of iron.
HELLPPP CAN SOMEONE SOLVE THIS???
Answer:
Density if iron shot = 7.92 g/ml (2 sig. figs.)
Explanation:
By definition, density is mass per unit volume. That is,
Density (D) = mass(m)/Volume(V)
mass(m) = 28.5g (given)
Volume(V, of iron shot) = 49.10ml - 45.5ml = 3.6ml
Substitutuing into D = m/V = 28.5g/3.6ml = 7.9166667 g/ml (calc.ans)
≅ 7.92 g/ml (2 sig. figs.)
Hope this helps. :-)
What is the mass of a baseball that has kinetic energy of 105 and is traveling at 10 m/s
Answer:
K.E =1/2 Mass×(velocity)2
Explanation:
1/2mass=K.E/Velocity 2
1/2mass=105/(10m/s)2
1/2mass=105/100m/s
1/2mass=21/20m/s
mass=21/20m/s ×2
mass=21/10
mass=2.1 Kilogram (put the value)
where does fertilization occurs in human beings
In human beings fertilization occurs in fallopian tube
Answer:
Fertilization usually takes place in a fallopian tube that links an ovary to the uterus. If the fertilized egg successfully travels down the fallopian tube and implants in the uterus, an embryo starts growing.
Rank the given objects from having the biggest size to the smallest size Blood cells , virus, atom, electrons , paper
Answer:
paper, blood cell, virus, electron, atom
Explanation:
Calculate the pOH of an aqueous solution of .0.073 M LiOH
Considering the definition of pOH and strong base, the pOH of the aqueous solution is 1.14
The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution and indicates the concentration of ion hydroxide (OH-).
pOH is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:
pOH= - log [OH⁻]
On the other hand, a strong base is that base that in an aqueous solution completely dissociates between the cation and OH-.
LiOH is a strong base, so the concentration of the hydroxide will be equal to the concentration of OH-. This is:
[LiOH]= [OH-]= 0.073 M
Replacing in the definition of pOH:
pOH= -log (0.073 M)
pOH= 1.14
In summary, the pOH of the aqueous solution is 1.14
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brainly.com/question/16032912?referrer=searchResults brainly.com/question/13557815?referrer=searchResultsPlease help me I can’t figure it out
1. Calculate the wavelength of light with a frequency of 1.89 x 1018 Hz.
a
Answer:
1.92402 kilohertz
Explanation:
hope this helps
Answer:
• From wave equation :
[tex]{ \rm{v = f \lambda}}[/tex]
v is velocity, v = 3.0 × 10^8 m/sf is frequencylambda is the wavelength[tex]{ \rm{3.0 \times {10}^{8} = (1.89 \times {10}^{18}) \times \lambda}} \\ \\ { \rm{ \lambda = \frac{3.0 \times {10}^{8} }{1.89 \times {10}^{18} } }} \\ \\ { \boxed{ \rm{ \: \lambda = 1.587 \times {10}^{ - 10} \: }}}[/tex]
A chemical reaction takes place in a closed system. The mass of the reactants before the reaction was grams. What must the mass of the products of the reaction be, according to the law of conservation of mass?
A. 35 grams B. 30 grams C. 70 grams D. 25 grams
Answer:
D. 25 grams
Explanation:
I think that's what the answer is
Which two phrases describe the movement of thermal energy due to
convection currents in the water on Earth?
O A. From the bottom of the ocean to the surface
B. From the surface of the ocean to the bottom
C. From cooler parts of Earth to the equator
D. From the equator to cooler parts of Earth
Answer:
D. From the equator to cooler parts of Earth
Explanation:
Thermal energy is always transferred from an area with a higher temperature to an area with a lower temperature. Moving particles transfer thermal energy through a fluid by forming convection currents.
Answer:
B. From the surface of the ocean to the bottom
D. From the equator to cooler parts of Earth
Explanation:
Test approved
Increasing the frequency _________________ the wavelength. Group of answer choices decreases increases does not change
Answer:
heightens
Explanation:
similarities between viruses and fungi
Answer:
I can't think of any similarities at all.
Viruses are just an aggregation of genomic material and protein. Occasionally lipid folds around it to make a covering called an envelope.
Fungi are living, eukaryotic cells that metabolize, grow, perform energy conversions and mate with each other.
does xef4 have resonance structure?
Answer:
Yes
Explanation:The structure of XeF4 is square planar.
I may need some help with this one
Answer:
ssihh add then htit da
Explanation:
Describe how you could show by adding aqueous sodium hydroxide and aqueous ammonia that a solution contained zinc ions.
Result with sodium hydroxide
Excess sodium hydroxide
Result with aqueous ammonia
Excess aqueous ammonia
Answer:
*result with sodium hydroxide: white ppt of Zn(OH)2
*excess sodium hydroxide: Precipitate dissolves to form a COLOURLESS solution
*Result with Aqueous ammonia: White ppt of Zn(OH)2
*excess aqueous ammonia: Precipitate dissolves to form a COLOURLESS solution
How many hydrogen atom are in compound NH42CO3
Answer:
There are 4 Hydrogen atoms in the compound NH42CO3
Explanation:
The "H4" is used to represent the amount of Hydrogen atoms in the compound itself, which is 4.